Fluid cylinders, such as pneumatic cylinders and hydraulic cylinders, are used in many industrial processes due to their capability for producing great forces through their use of relatively simple and inexpensive constructions. Fluid cylinders typically operate by forcing a fluid into a chamber that causes an actuator to move, for instance, in a linear direction. The actuator may be moved, for instance, by applying air or liquid pressure to the actuator. In order for the device to work properly, the actuator generally needs to form a tight seal against the walls of the channel in which the actuator moves.
In the past, in order to form a seal between the actuator and the walls of the housing, various lubricants and sealing polymers, such as O rings, were used. Conventional sealing methods, however, are generally not designed to be used in high temperature applications. For example, many sealing polymers and composite bearing elements typically do not have operating ranges exceeding about 400° F. As such, a need currently exists for a fluid cylinder that may be used in high temperature applications. For example, a fluid cylinder is needed that is capable of withstanding a continuous operating temperature of greater than about 600° F.